1. Field of the Invention
The present invention generally relates to a mobile communication terminal for handover from a WCDMA network to a CDMA network and method therefor, and more specifically, to a technology of installing a WCDMA beacon cell in a CDMA cell to indirectly measure a CDMA cell power level through measurement of a WCDMA beacon cell power level, thereby performing a handover effectively.
2. Description of the Related Art
A handover refers to a function of automatically converting a communication channel of a current cell into that of the other cell to keep communication continued when a mobile communication terminal moves from the current cell to the other cell. A general method for converting a communication channel is as follows. First, a base station of a current cell measures a received signal strength indication (RSSI) of a communication channel, and informs a switching center when the strength decreases below a regulation level. Then, the switching center searches an available channel of a predetermined neighbor group list to convert the communication channel.
The handover is performed among cells using the same radio access technology (hereinafter, referred to as “RAT”) as well as those using different RATs, for example, cells of a CDMA network and a WCDMA network.
When the handover is performed among cells using the different RATs, it is important to measure a cell power level of the different RAT. For example, call connection may be disconnected when a blind handover is performed without measurement of the cell power level of the different RAT.
However, when a handover is performed from a WCDMA cell to a CDMA cell under a current 3GPP standard, there is no method for reporting information on the power level of the CDMA cell. That is, a field for reporting the information under the 3GPP standard is not defined. As a result, there is a limit in proliferation of WCDMA under a communication circumstance of CDMA.